Cujo,
My daily driver is black. (you would think I would save that color for the garage!) I drive a black ford ranger pickup each day and I have a charcoal 400E Benz and a cashmere Lexus LX470 in the garage (the wifes car). The black sits in the driveway and deals with the salt air from driving each day. It is a PITA to say the least. If I let the EX sit for at least 3 hours my daily life is good with S&W and an MF. If I use a quick on and off with EX (less than one hour) I am the smudge king with the S&W (humidity and salt combo). Not sure what you guys experience, but that is my scenario. Would like to hear some other advice and possibilities.